/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.ha.backend;

import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;

import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MulticastSocket;
import java.nio.charset.Charset;

/*
 * Sender to proxies using multicast socket.
 */
public class MultiCastSender
		implements Sender {

	private static final Log log = LogFactory.getLog(HeartbeatListener.class);
	private static final Charset US_ASCII = Charset.forName("US-ASCII");

	HeartbeatListener config = null;

	/* for multicasting stuff */
	MulticastSocket s = null;
	InetAddress group = null;

	@Override
	public void init(HeartbeatListener config) throws Exception {
		this.config = config;
	}

	@Override
	public int send(String mess) throws Exception {
		if (s == null) {
			try {
				group = InetAddress.getByName(config.getGroup());
				if (config.host != null) {
					InetAddress addr = InetAddress.getByName(config.host);
					InetSocketAddress addrs = new InetSocketAddress(addr, config.getMultiport());
					s = new MulticastSocket(addrs);
				} else
					s = new MulticastSocket(config.getMultiport());

				s.setTimeToLive(config.getTtl());
				s.joinGroup(group);
			} catch (Exception ex) {
				log.error("Unable to use multicast: " + ex);
				s = null;
				return -1;
			}
		}

		byte[] buf;
		buf = mess.getBytes(US_ASCII);
		DatagramPacket data = new DatagramPacket(buf, buf.length, group, config.getMultiport());
		try {
			s.send(data);
		} catch (Exception ex) {
			log.error("Unable to send collected load information: " + ex);
			s.close();
			s = null;
			return -1;
		}
		return 0;
	}

}
